The present invention relates to a folding hood for motor vehicles, and more particularly, to a hood frame which supports the hood cover and can be folded open in order to stretch the hood cover, and a reinforcement of the stretched hood cover, adjoining a strut supporting the latter, by way of a shaping shell mounted between the strut and the hood cover, which, because of its dimensional rigidity, interacts in a shaping manner with the hood cover resting flat thereon. The shaping shell is positioned under the hood cover via tensile connectors extending transversely to the strut and stretched tightly when the hood frame is folded open.
A folding hood is disclosed, for example, in EP-PS 0 189 649, in which the shaping shell is fixed to the central region of the corner strut and is thus pivotable, together with the corner strut, relative to the hood cover. The surface of the shaping shell which faces the hood cover has a conformation, as seen in cross-section, which is adapted to the intended corner contour of the folding hood. A strap extends on each side of a rear window in the folding hood and is attached by its front end to a main strut and by its rear end to a material-retaining hoop of the folding hood. When the material-retaining hoop and the main strut are folded apart, the two straps are increasingly tightened, together with the hood cover, as a result of which they are stretched substantially straight when the hood is closed. Since the two straps are also connected to the corner strut, the latter is entrained by the extending straps into its end position, with the shaping shell also entering its reinforcing position.
When the vehicle roof is open, the folding hood is retracted into a hood box on the body work. For this purpose, the main strut, the corner strut and the material-retaining hoop are folded one upon the other in a space-saving manner. This space-saving storage position, in which the hood cover and the straps are slackened and lay between the folded-together frame parts, is, however, only readily possible because the shaping shell, seen in cross-section, only has a width which approximately corresponds to twice the cross-sectional width of the corner strut. If, by contrast, the width of the shaping shell were significantly increased in order to provide a shaping reinforcement for a larger surface area of the hood cover, the shaping shell would make a similarly compact storage position impossible because of its transverse extent relative to the plane of the folded-together frame parts.
An object of the present invention is to provide a folding hood of the aforementioned type such that compact folding of the stored folding hood remains possible even with a larger-sized shaping shell for the shaping reinforcement of the hood cover.
This object has been achieved in accordance with the invention by configuring the shape shell to be transversely deformable, in a flexurally resilient manner, about a longitudinal axis extending along its bearing position on the strut. When the folding hood is open, the shell is retained in a relaxed initial position, and when the folding hood is closed, the shaping shell can be bent into its shaping position of use by way of the tensioning advance of the tensile connecting apparatus.
In principle, it is possible here to retain the arrangement of the shaping shell on the supporting strut. To do this, the projecting cross-sectional width of the shaping shell in its relaxed initial position has to extend approximately parallel to the plane outlined by the strut supporting it. In the simplest case, moreover, it is possible for the hood cover itself to form the tensile connecting apparatus. However, this requires a hood material of low extensibility.
Because of the outward angling of the exterior contour in the corner-strut zone of the folding hood, it is expedient in accordance with the present invention to reinforce the V hood cover in a surface area lying in front of and behind the corner strut. A proven way of doing this is a shaping shell which is curved in an arcuate manner and is moved, independently of the corner strut, via tensile connecting apparatus. In its position of use, the shaping shell is more sharply angled outwards than in its relaxed initial position. In this arrangement, it is also readily possible to pivot the corner strut under the shaping shell which still has a low curvature. This is even more the case if the corner strut consists of a metal profile with a round cross-section which interacts with a shaping shell of slip promoting metal or of plastic.
A stable, rocker-type bearing position of the shaping shell on the corner strut can be achieved via tensile apparatus which are stretched forwards and backwards and by way of which the front and back edge zones of the shaping shell are stretched in opposite directions.
The forward stretching is cost-effectively achieved by a plurality of straps leading from the main strut.
The rearward stretching of the shaping shell is performed by a combination of a strip of hood cover, a rigid rear window and short straps. This combination is arranged between the shaping shell and the material-retaining hoop. As a result, structural parts which are in any case present are advantageously utilized as tensioning apparatus.
As a consequence, moreover, of the short, film-hinge-type connection of the rear window to the shaping shell, in combination with the restoring force of the flexurally deformed shaping shell, a permanent tilting support of the rear window is achieved in a simple manner. This tilting support makes it possible to prevent sagging of the rear window which occurs especially in the case of heavy rear windows made from mineral glass because of the fact that the region of the hood cover enclosing the rear window extends excessively.
The film-hinge-type connection can advantageously be made via a plurality of short straps which engage on the shaping shell in a manner which is a mirror image of the front straps. Therefore, it is possible to achieve substantially uniform flexural deformation of the shaping shell over its length.
A masked attachment of the straps to the rear window can be simply achieved via a window frame enclosing the rear window.
A tapering of the two end regions of the shaping shell to the side of the rear window present the function of the shaping shell from being impaired, and there is little impediment to the foldability of the hood cover in the lateral wall region.